Twin-wire presses for dewatering of a fiber suspension and forming of a continuous web thereof are previously known. Dewatering of the pulp is usually done from an inlet pulp concentration of 3-8 percentages by weight to an outlet pulp concentration of 30-50 percentages by weight. According to the state of the art, such twin-wire presses comprises lower rolls, an endless lower wire running in a path around the lower rolls, upper rolls, and an endless upper wire running in a path around the upper rolls. The two wires co-operate with each other along sections of said paths that run substantially in parallel with each other for dewatering of the fiber suspension between the wires during displacement thereof. An inlet box provides for supply of the fiber suspension to a wedge-shaped dewatering space between the wires. The twin-wire press further comprises two dewatering tables supporting the respective wire in said sections of the path and forming the wedge-shaped dewatering space between the wires for initially pressing and dewatering the fiber suspension, whereby a web is formed between the wires, and a roll arrangement situated after the dewatering tables in said sections of the paths, as seen in the direction of movement of the wires, for finally pressing and dewatering the web between the wires, so that the web will get a desired dryness.
It is often necessary in a simple way and as quickly as possible at maintenance, exchange of wire and cleaning of the twin-wire press, without prolonged stoppage of production, to be able to reach the dewatering apace between the upper and lower dewatering tables. An apparatus for lifting of the upper table in twin-wire presses is known, which is a lifting apparatus integrated in the press that is arranged to lift up the side of the upper dewatering table, hereinafter denoted the front edge, that is adjacent the roll arrangement. A rear edge of the dewatering table remains in the original position. The known lifting apparatus only permits a limited lifting of the upper dewatering table, and only of its front edge, which means that the accessibility to those areas of the dewatering space that are situated in vicinity of the rear edge of the upper and lower dewatering tables still are restricted, whereby maintenance, exchange of wire and cleaning is time-consuming and circumstantial.
One object of the present invention is to achieve an easier, more effective and improved twin-wire press where the whole dewatering space is easily accessible for maintenance, exchange of wire and cleaning if required, and where at least those drawbacks that are associated with previously known state of the art can be partially eliminated. Another object is to provide a twin-wire press where maintenance, exchange of wire and cleaning of the press can be carried out cost efficiently and in a work saving way.